使用百度地图API产生指定范围的随机点

直接上代码：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title></title>
    <script type="text/javascript" src="http://api.map.baidu.com/api?v=2.0&ak=1nCQCnDr3Nt3GKDVeBmKGe2Y"></script>
<script type="text/javascript" src="http://api.map.baidu.com/library/GeoUtils/1.2/src/GeoUtils_min.js"></script>

</head>
<body>
    <div id="allmap" style="1000px;height:500px"></div>
    <div id="divInfo"></div>
</body>
</html>
<script type="text/javascript">
    window.onload = function () {
        var map = new BMap.Map("allmap");
        map.centerAndZoom(new BMap.Point(106.258277, 29.498607), 5);
        map.enableScrollWheelZoom();


        var bdary = new BMap.Boundary();
        bdary.get("沙坪坝区", function (rs) {       //获取行政区域
            map.clearOverlays();        //清除地图覆盖物       
            var count = rs.boundaries.length; //行政区域的点有多少个
            if (count === 0) {
                alert('未能获取当前输入行政区域');
                return;
            }
            var pointArray = [];
            for (var i = 0; i < count; i++) {
              
                var ply = new BMap.Polygon(rs.boundaries[i]); //建立多边形覆盖物
                map.addOverlay(ply);  //添加覆盖物
                pointArray = pointArray.concat(ply.getPath());
                map.setViewport(pointArray);

                var res = "", minX = 106.258277, minY = 29.498607, x = 0, y = 0,pt=null;

                for (var i = 0; i < 2000; i++) {
                    x = minX + getRandom();
                    y = minY + getRandom();
                    pt = new BMap.Point(x, y);
                    if (BMapLib.GeoUtils.isPointInPolygon(pt, ply)) {
                      
                        var marker = marker = new BMap.Marker(new BMap.Point(x, y));

                        map.addOverlay(marker);
                        //res += 'marker = new BMap.Marker(new BMap.Point(' + x + ' ,' + y + '));<br/>map.addOverlay(marker);<br/>  ';
                    }
                }

                divInfo.innerHTML = res;
            }
           // map.setViewport(pointArray);    //调整视野  
            //addlabel();
        });


        //document.getElementById("divInfo").innerHTML = Math.random()/4;
       
    }


    function getRandom() {
        return Math.random() / 2;
    }
</script>
运行效果图